The present invention relates to a system for monitoring the operation of output transducers of a central control and monitoring unit for machines and/or devices usable in production and or product packaging lines, for example, cigarette production lines and/or cigarette packet packaging lines; such lines can, for example, include cigarette making machines, filter fitting machines, packaging machines, cellophane wrapping machines, carton making and parcel forming machines.
As is known, such individual machines or production lines are controlled by a central control and monitoring unit, which in dependence on certain signals emitted by input transducers, determine, at suitable instants, the operations of the various output transducers which can also belong to different machines in the same line.
Signals from such input transducers arrive at the central control and monitoring unit via associated input circuits. Further, the central control and monitoring unit also effects the detection of the effect of the controls on the output transducers, via associated monitoring circuits which detect a voltage drop caused by the signal directed to the output transducer.
Such monitoring circuits are coupled to the central unit by means of associated input circuits. Upon detection of a defect in the transfer of control signals to the output transducers, the central unit activates a fault indicator and stops the machine.